Imaging Findings of Smoking-related Pulmonary Parenchymal Disease

Cigarette smoking is a major cause of parenchymal lung disease, with a wide range of imaging findings that radiologists must be able to recognize. These include chronic obstructive pulmonary disease (COPD) and a group of diffuse interstitial lung diseases (ILDs) collectively referred to as smoking-related ILDs (SR-ILDs), which encompass inflammatory and fibrotic processes induced by smoking. Although many of these conditions exhibit characteristic imaging features, significant overlap is common, and multiple entities may coexist in the same patient and add difficulty to the diagnostic process. The distinction between SR-ILDs and other ILDs is critical, as they differ in behavior, prognosis, and management. CT of the chest plays a pivotal role in allowing radiologists to identify characteristic features, distinguish overlapping patterns, and guide multidisciplinary evaluation. The authors provide a comprehensive review of smoking-related parenchymal lung diseases, focusing on clinical, histopathologic, and especially radiologic features. The authors also review emerging inhalation injuries associated with e-cigarette and marijuana use, which further expand the spectrum of imaging findings. Radiologist awareness of these imaging manifestations is essential for improving diagnostic accuracy and guiding appropriate management. ^©RSNA, 2026 Supplemental material is available for this article.